Starter.



V. BENDIXl STARYER. APPLICATION msn MAR. l5, |916.

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UNITED STATES PATENT OFFICE.

VINCENT BENDIX, OF CHICAGO, ILLINOIS.

STARTER.

Application filed March 15, 1916.

1,125,935. My invention concerns that part of a starting device known asa transmission or drive for transmitting the power of a prime mover suchas an electric motor to some member of the engine to be started.

such as 'its ily wheel. In my type of starter the drive includes a screwshaft operated by the prime mover either directly or indirectly, andhaving mounted thereon aL driving member in the form of Ia pinion,adapted to engage or mesh with the fly wheel or other engine member forrotating the crank shaft thereof in the starting operation. The objectof my invention` is to improve the resilient driving connection betweenthe prime mover and the screw shaft by providing a coiled spring of aformation especially adapted for its particular purposes and functions.

In drives of this type there is a possibility of the coils of the springbecoming displaced in the coiling action, that is when the power isbeing transmitted from the motor to the screw sleeve or shafton whichthe driving pinion is mounted. In case ofsuch displacement there will bea binding between the spring and associated parts as well as thepossibility of a displaced coil dropping between two of such parts wheremovement is desired. It is therefore necessary to employ a spring whosecoils will not thus become displaced and at the saine time provide forfree compression and eX- pansion of such spring longitudinally. Speakingin general terms I-have overcome the difliculties in question byproviding a spring whose coils are elliptical in crosssection with thelonger diameters at right angles to the axis of the coils of the spring.

In the drawings Figure 1 is a section of my transmission or driveembodying my invention and showing a part of the prime mover or shaftactuated thereby, and a part of the engine member such as the fly wheel;and Fig. 2 a perspective of the coiled spring.

Referring to the embodiment of my in- Specification of Letters Patent.

Patented Mar. 5, 1918.

Serial No. 84,463.

vention as herein shown, the prime mover (not shown) which may be in theform of an electric motor, is adapted to actuate a driving shaft 1,either directly or indirectly, in the manner clearly shown in my patentaforesaid. Upon the inner portion of this shaft there is mounted asleeve 2 which is free thereon, and also capable of some oscillation andlongitudinal movement. This sleeve is provided eXteriorly intermediateits length with screw-threads, on which is mounted to screw a pinion 3,having teeth adapted to mesh with corresponding teeth 4 on the fly wheel5 of the engine. This sleeve has at its inner end a stop nut 6.

A resilient driving connection is provided between the shaft 1 and thesleeve 2, the same comprising a coiled spring 7 anchored at one end t0the shaft and at the other end to the sleeve. According to the specificconstruction herein shown, a spring barrel 8 is arranged concentricallyof the shaft 1 and held in place at the outer end thereof by means of apin or bolt 9, which also forms the means for anchoring the outer end ofthe spring 7. The other end of the spring is anchored to a stud or bolt10, screwing into the outer end of the sleeve 2. The sleeve and springbarrel are arranged in axial alinement but not in contact, inasmuch as aspace 11 is left therebetween, in order that the sleeve may have aslight movement outwardly against the tension of the spring.

As shown in the drawings the coils of the spring are elliptical incross-section, with the result that, their longer diameters arepresented in line with the stress due to the coiling action, therebygiving the greatest possible strength with a given amount of metal. Alsothis form of spring prevents displacement of any one or more of thecoils which would have a tendency to bind upon the spring barrel, or toslip into the space 11 and prevent the eiid-wise movement above referredto. Furthermore this formation of spring provides a very freecompression and expansion of the spring consistent with the greatstrength thereof with respect to the coiling action, it being understoodthat the power of the motor is transmitted through this spring to thescrew sleeve or shaft. This form of spring provides the suflicientamount of strength for the objects in view, and at the same time permitsof the closest possible istance between the anchoring bolts.

While I have herein shown and described my invention in connection witha certain construction of transmission or drive, yet it will beunderstood that it is not limited to any specific construction, forinstance, while I have herein shown the screw shaft as of the hollowor`sleeve form, yet my invention is equally applicable to the constructionemploying the solid form of screw shaft as shown, for instance, in myprior Patent No. 1,146,992, issued to me on July Q0, 1915.

I claim:

l. For use in transmission mechanism in engine starting apparatus, aspring coperating\ with such mechanism and forming a yielding drivingconnection therein in the line of transmission of power, said springbeing of the coiled type and having its coils flattened in a directionat right angles to the axis of the coil. l

2. For use in transmission mechanism in engine starting apparatus, aspring coperating with such mechanism and forming therein in the line oftransmission of power a driving connection having a yielding torsionalaction and a yielding longitudinal action, said spring being of thecoiled type and having its coils flattened at right angles to the axisof the coil to provide the strength for said torsional action and theresiliency for said longitudinal action.

3. For use in transmission mechanism in engine starting apparatus, aspring coperating with such mechanism and forming a yielding dri-vingconnection therein between different rotatable members of thetransmission mechanism, said spring being of the coiled type and havingits coils flattened in a direction at right angles to the axis of thecoil.

4. In engine starting apparatus, a transmission mechanism including tWorotatable members, one of which has a longitudinal movement, and ayielding driving connection between such members consisting of a Acoiled spring having its coils flattened in a direction at right anglesto the axis of the coil and arranged for torsional and for extension andcompression actions.

5. In engine starting apparatus, a transmission mechanism including arotatable shaft, a driving member mounted thereon, and a yieldingdriving means for driving the shaft consisting of a coiled spring havingits coils flattened in a direction at right angles to the axis of thecoil.

6. In engine starting apparatus, a transmission mechanism including arotatable shaft, a driving member mounted thereon, and a yieldingdriving, means for driving the shaft consisting of a coiled springconneeeoa nected with and encircling the shaft and having'its coilsflattened in a direction at right angles to the axis of the coil,

7. In engine starting apparatus, a tra-nsmission mechanism including arotatable shaft, a driving member mounted thereon, and a yieldingdriving means for driving the shaft consisting of a coiled spring havingits coils flattened in a direction at right angles to the axis of thecoil, said shaft having a limited longitudinal movement against thetension of such spring.

8. The combination of a motor, a driving member, operating lmeansbetween the motor and driving member for causing automatic engagement ofthe motor with and disengagement of the same from a member of the engineto be started, said means including a resilient driving connectionconsisting of a coiled spring, whose coils are flattened in a directionat right angles to the axis of the coil.

9. In transmission mechanism for an engine starter, the combination of arotatable screw shaft, a driving member mounted thereon for longitudinalmovement thereon and rotary movement therewith, and a resilient drivingconnection for the screw shaft consisting of a coil spring, whose coilsare flattened in a direction at right angles to the axis of the coil.

l0. In transmission mechanism for an engine starter, the combination ofa rotatable screw shaft, a driving member mounted thereon forlongitudinal movement thereon and rotary movement therewith, and aresilient driving connection for the screw shaft consisting of a coilspring whose coils are substantially elliptical in cross-section withthe greater diameter at substantially right angles to the axis of thecoil and to the axis of the screw shaft.

11. In transmission mechanism for an engine starter, the combination ofa rotatable screw shaft, a driving member mounted thereon forlongitudinal movement thereon and rotary movement therewith, a drivingshaft, a coil spring forming a resilient driving connection between thescrew shaft and the driving shaft, anchoring bolts connected With saidshafts respectively, and adapted VINCENT BENDIx.

Witnesses:

S. E. HIBBEN, ROBERT DonnMAN.

